Retrieval of documents from many incompatible repositories is a difficult problem. In the event that documents are searched in many servers on a network using a single FIND command, the possibility that the servers, and the repositories running on the servers, are incompatible has a high probability.
There is needed a system for searching, and retrieving, documents from a heterogenous collection of diverse servers. Even servers implemented on the same model of computer may have incompatible data base programs running on each server. And modern networks connect many computers made by different manufacturers, each running database software which is incompatible with the data base software running on the other servers.
There is needed a solution to the complex problem of retrieving documents from many mutually incompatible computers. The retrieval, ideally, operates efficiently and seamlessly for a large number of servers coupled to a large network.